1916.] Fauna of the Chilka Lake ; Mollusca Gastropoda, etc. 345 



caking mud. No specimens were seen in the freshwater season. Mr. Townsend 

 draws attention to the tenacity of life exhibited by this mollusc. 1 



The species is abundant in mangrove swamps on the coasts of India and the 

 Malay Archipelago : in the Gangetic delta the shell is one of those most commonly 

 used for making lime. Dead shells in the outer channel of the Chilka L,ake were 

 sometimes occupied by the hermit-crab Clibanarius padavensis. 



The distribution is similar to that of the former species. 



Family Turritellidae. 



Vanesia rambhaënsis, Preston, 1914, p. 297, figs. 5, $a (as Terebra) ; 1915, P- 289 ; 

 1916, p. 32. 



V. rambhaënsis is widely distributed on the bed of the main area of the lake 

 and was also taken at the inner end of the outer channel. Although it was originally 

 described from a single specimen the species appears to be gregarious. It was found 

 in large numbers among dead vegetation in Madarchua Bay at the south end of the 

 lake in July. We obtained no specimens in the outer channel in the salt-water 

 season. The species is also known from the Cochin backwaters. 



Family Fossaridae. 



Chilkaia imitatrïx* Preston, 1915, p. 291, figs. 1, la. 



Four specimens, including the type of the genus and species, were taken in the 

 inner part of the outer channel in September. Preston remarks on the superficial 

 resemblance of the shell to that of certain forms of Paramelania characteristic of the 

 fauna of Lake Tanganyika ; but there can of course be no real affinity. The species 

 is evidently very scarce. 



Family Litiopidae. 



Litiopa (Alaba) kempt * Preston, 1914, p. 300, figs. 3, 3a; 1915, p. 292. 



This species occurs sparingly all over the main area of the lake and was found 

 in the outer channel in the freshwater season. It lives among weeds on either a 

 sandy or a muddy bottom. 



Litiopa (Alaba) copiosa* Preston, 1915, p. 292, figs. 2, 2a. 



L. copiosa was found in enormous numbers at both seasons of the year in the 

 channels between Barnikuda and Satpara, between the latter place and Mahosa and 

 in Seruanaddi. It also occurred more sparingly in the neighbourhood of Nalbano. 



Family Hydrobiidae. 



This family is represented by one species of Hydrobia and six forms of Stenothyra, 

 all of which Mr. Preston regards as distinct species. Eleven Indian species of Steno- 

 thyra are now recognized by him 2 , most of which were described from brackish 

 water. It seems not improbable to us that, when large series from different localities 



1 See Melvill and Stauden, Proc. Zool. Soc. London, 1901, p. 375. 



2 Faun. Brit. Ind., Freshwater Mollusca, p. 79 (1915) and Rec. Ind. Mus., XII. p. 31 (1916). 



